Reciprocating pump

ABSTRACT

The present invention provides a pump having a compact and lightweight design, which enables an improvement in pump efficiency and a reduction in noise. The pump comprises a manifold having a pump chamber, a suction port for sucking fluid from the outside to the inside of the manifold, a discharge port for discharging fluid from the inside to the outside of the manifold, a suction valve which is provided between a suction port and a pump chamber, and opens and closes a flow path of fluid to the pump chamber, and a discharge valve which is provided between the pump chamber and the discharge port, and opens and closes a flow path of fluid from the pump chamber. Furthermore, the suction port, the suction valve, the discharge valve and the discharge port are arranged coaxially, thereby the fluid does not meet unnecessary resistance, the fluid is made to flow smoothly, pump efficiency can be improved, noise can be reduced, and the structure of the manifold can be simplified and made compact and lightweight.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a reciprocating pump.

2. Related Background Art

In a conventional reciprocating pump such as a plunger pump or a piston pump, a flow path inside a manifold curves in an approximately perpendicular direction between a suction port and a suction valve, and then curves in an approximately perpendicular direction between a discharge valve and a discharge port as described, for example, in Japanese patent No. 3983185.

Here, when the aforementioned reciprocating pump is operated, fluid sucked from the suction port flows along the flow path to a pump chamber and then is discharged from the pump chamber to the outside through the discharge port. However, at this time, the fluid passing through the inside of the manifold meets great resistance, which may result in problems such as noise or degradation of pump efficiency.

Furthermore, the shape of the manifold is complicated due to the complicated arrangement of the suction port, the suction valve, the discharge valve and the discharge port, and compact and lightweight design of the pump is therefore difficult.

SUMMARY OF THE INVENTION

The present invention was made to solve such problems and its object is to provide a reciprocating pump that has a compact and lightweight design and enables an improvement in pump efficiency and a reduction in noise.

The reciprocating pump of the present invention is a reciprocating pump for performing pumping in a pump chamber constituting an end of a cylinder by a reciprocating member reciprocating inside of the cylinder, and comprises: a manifold having the pump chamber; a suction port for sucking fluid from an outside to an inside of the manifold; a discharge port for discharging fluid from the inside to the outside of the manifold; a suction valve for opening and closing a flow path of the fluid to the pump chamber, the suction valve being provided between the suction port and the pump chamber; and a discharge valve for opening and closing a flow path of the fluid from the pump chamber, the discharge valve being provided between the pump chamber and the discharge port, the suction port, the suction valve, the discharge valve and the discharge port being arranged coaxially.

According to this reciprocating pump, since the suction port, the suction valve, the discharge valve and the discharge port are arranged coaxially, fluid flows without meeting unnecessary resistance, and therefore the fluid can be made to flow smoothly, pump efficiency can be improved, and noise can be reduced. Furthermore, as described above, since the suction port, the suction valve, the discharge valve and the discharge port are arranged coaxially, the structure of the manifold can be simplified and made compact and lightweight.

It is preferable that the manifold is fixed by a plurality of bolts to a casing accommodating a drive source side of the reciprocating member, and the bolts are mounted in equidistant positions on the same circumference viewed in a axial direction of the cylinder.

According to this reciprocating pump, since the configuration of the manifold is simplified by arranging the suction port, the suction valve, the discharge valve and the discharge port coaxially as described above, the degree of freedom of the arrangement of the plurality of bolts for fixing the manifold to the casing is increased, and the bolts can be mounted in equidistant positions on the same circumference viewed in the axial direction of the cylinder. The manifold can thereby be mounted to the casing in various rotational positions with a cylinder axis as a central axis, making installation of the reciprocating pump more convenient.

The reciprocating pump of the present invention enables an improvement in pump efficiency and a reduction in noise, with a compact and lightweight design.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal sectional view of a reciprocating pump of an embodiment of the present invention;

FIG. 2 is an elevational view of the reciprocating pump shown in FIG. 1; and

FIG. 3 is an elevational view of a casing in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment of the reciprocating pump of the present invention will be described below with reference to FIGS. 1 to 3. In addition, up, down, left and right directions indicate the directions in the descriptive figures unless specified otherwise.

FIG. 1 is a longitudinal sectional view of a reciprocating pump of an embodiment of the present invention, FIG. 2 is an elevational view of the reciprocating pump, and FIG. 3 is an elevational view of a casing. In addition, a section above the axis A of a plunger (reciprocating member) 5 shown in FIG. 1 shows a case where the plunger 5 is at the top dead center, and a section below the axis A shows a case where the plunger 5 is at the bottom dead center.

As shown in FIG. 1, the external form of a reciprocal pump 100 is configured with a casing 1 coupled to a manifold 6, and a tubular cylinder 18 is provided therein so as to extend in left and right directions of FIG. 1. Furthermore, a plunger 5 is provided inside the cylinder 18.

A con rod 2, a piston pin 4 and a cam shaft 3 serving as the drive source of the plunger 5 are arranged inside the casing 1. On the side close to the manifold 6 of this casing 1, bolt holes 19 are provided in equidistant positions on the same circumference viewed in the axial direction of the cylinder 18 as shown in FIG. 3, and particularly in the present embodiment, are provided in four equidistant positions (positions each separated by 90° in a circumferential direction). The manifold 6 is coupled to the casing 1 by screwing four bolts 14 into the bolt holes 19 as shown in FIG. 2.

In addition, a high-pressure seal 20 and a low-pressure seal 21 for preventing leakage of fluid between the cylinder 18 and the plunger 5 are arranged in the cylinder 18 in liquid-tight slidable contact with the outer circumferential surface of the plunger 5 as shown in FIG. 1.

Furthermore, pumping is performed wherein the plunger 5 reciprocates inside the cylinder 18 in the left and right directions of FIG. 1 via the con rod 2 and the piston pin 4 by rotation of the cam shaft 3, a pump chamber 17 comprising an end of the cylinder 18 (the left end of FIG. 1) is pressurized/depressurized, and fluid is sucked in and discharged.

The suction port 12 for sucking fluid from the outside to the inside of the manifold 6 is provided below the pump chamber 17 of the manifold 6, a flow path 22 communicating the suction port 12 and the pump chamber 17 is provided between this suction port 12 and this pump chamber 17, and a suction valve 11 opening and closing this flow path 22 is provided in this flow path 22. In addition, above the pump chamber 17, an adapter 9 provided with a discharge port 13 for discharging fluid from the inside to the outside of the manifold 6 is mounted on the manifold 6, a flow path 23 communicating the discharge port 13 and the pump chamber 17 is provided between the discharge port 13 of the adapter 9 and the pump chamber 17, and a discharge valve 7 opening and closing this flow path 23 is provided in this flow path 23.

This suction valve 11 and this discharge valve 7 have approximately round dish-shaped valve discs 11 a and 7 a opening and closing flow paths 22 and 23, approximately cylindrical valve seats 11 b and 7 b where the valve discs 11 a and 7 a unseat/seat, compression springs 11 c and 7 c biasing the valve discs 11 a and 7 a in the seating direction, and approximately cylindrical holding members 11 d and 7 d accommodating the valve discs 11 a and 7 a and the compression springs 11 c and 7 c.

Furthermore, the suction valve 11 is configured such that when the plunger 5 moves to the bottom dead center and depressurizes the inside of pump chamber 17, the valve disc 11 a resists the biasing force of the compression spring 11 c and unseats upward from the valve seat 11 b, opening the flow path 22 and sucking fluid from the outside through the suction port 12. Meanwhile, the discharge valve 7 is configured such that when the plunger 5 moves to the top dead center and pressurizes the inside of the pump chamber 17, the valve disc 7 a resists the biasing force of the compression spring 7 c and unseats upward from the valve 7 b, opening the flow path 23 and discharging fluid to the outside through the discharge port 13.

Here, particularly in the present embodiment, the suction port 12, the flow path 22, the suction valve 11, the pump chamber 17, the discharge valve 7, the flow path 23 and the discharge port 13 are arranged coaxially to form a straight line. Furthermore, these members are arranged in a line on an axis B orthogonal to the axis A of the plunger 5.

Furthermore, a cooling line 24 connected between a high-pressure seal 20 and a low-pressure seal 21 is connected to the flow path 22, some of the fluid sucked through the suction port 12 is supplied to the plunger 5 through the cooling line 24, and the plunger 5 is thereby cooled by the fluid.

According to this reciprocating pump 100, the reciprocating pump 100 is actuated, the plunger 5 reciprocates, the fluid is sucked from the suction port 12, through the flow path 22 and the suction valve 11, and to the pump chamber 17, and then flows from the pump chamber 17, through the discharge valve 7 and the flow path 23, and is discharged from the discharge port 13.

At this time, since the suction port 12, the suction valve 11, the discharge valve 7 and the discharge port 13 are arranged on the same axis B, the fluid flows without meeting unnecessary resistance, and therefore the fluid can be made to flow smoothly, pump efficiency can be improved, and noise can be reduced. Furthermore, since the suction port 12, the suction valve 11, the discharge valve 7 and the discharge port 13 are arranged on the same axis B as described above, the structure of the manifold 6 can be simplified and made compact and lightweight.

Furthermore, according to the reciprocating pump 100, since the structure of the manifold 6 is simplified by arranging the suction port 12, the suction valve 11, the discharge valve 7 and the discharge port 13 on the same axis B as described above, the degree of freedom of the arrangement of the plurality of bolts 14 for fixing the manifold 6 to the casing 1 is increased, and the bolts 14 can be mounted in four equidistant positions each separated by 90° in a circumferential direction on the same circumference viewed in the axial direction of the cylinder 18. The manifold 6 can thereby be mounted on the casing 1 in four positions conforming with the top, bottom, left and right directions of FIG. 2, with (1) the suction port 12 on the bottom and the discharge port 13 on the top, (2) the suction port 12 on the left and the discharge port 13 on the right, (3) the suction port 12 on the top and the discharge port 13 on the bottom, and (4) the suction port 12 on the right and the discharge port 13 on the left. The installation of the reciprocating pump 100 can thus be made more convenient.

Although the present invention is described specifically above based on this embodiment, the present invention is not limited to the above embodiment. For example, although the number of bolts 14 for fixing the manifold 6 to the casing 1 is particularly preferably four in the above embodiment, this number is not limited and can be, for example, six or eight, as long as the bolts are arranged in equidistant positions on the same circumference viewed in the axial direction of the cylinder 18, and the manifold 6 can be mounted on the casing 1 in various rotational positions depending on this number. 

1. A reciprocating pump for performing pumping in a pump chamber constituting an end of a cylinder, by a reciprocating member reciprocating inside of the cylinder, the reciprocating pump comprising: a manifold having the pump chamber; a suction port for sucking fluid from an outside to an inside of the manifold; a discharge port for discharging fluid from the inside to the outside of the manifold; a suction valve for opening and closing a flow path of the fluid to the pump chamber, the suction valve being provided between the suction port and the pump chamber; and a discharge valve for opening and closing a flow path of the fluid from the pump chamber, the discharge valve being provided between the pump chamber and the discharge port, the suction port, the suction valve, the discharge valve and the discharge port being arranged coaxially.
 2. The reciprocating pump according to claim 1, wherein the manifold is fixed by a plurality of bolts to a casing accommodating a drive source side of the reciprocating member, and the bolts are mounted in equidistant positions on a same circumference viewed in an axial direction of the cylinder. 